title: Common heritable effects underpin concerns over norm maintenance and in-group favoritism: evidence from genetic analyses of right-wing authoritarianism and traditionalism.
abstract: Research has shown that in-group favoritism is associated with concerns over the maintenance of social norms. Here we present two studies examining whether genetic factors underpin this association. A classical twin design was used to decompose phenotypic variance into genetic and environmental components in two studies. Study 1 used 812 pairs of adult U.S. twins from the nationally representative MIDUS II sample. Study 2 used 707 pairs of middle-age twins from the Minnesota Twin Registry. In-group favoritism was measured with scales tapping preferences for in-group (vs. out-group) individuals; norm concerns were measured with the Multidimensional Personality Questionnaire-Traditionalism (Study 1) and Right-Wing Authoritarianism (RWA; Study 2) scales. In Study 1, heritable effects underlying traditionalism were moderately (c. 35%) overlapping with the genetic variance underpinning in-group favoritism. In Study 2, heritable influences on RWA were entirely shared with the heritable effects on in-group favoritism. Moreover, we observed that Big Five Openness shared common genetic links to both RWA and in-group favoritism. These results suggest that, at the genetic level, in-group favoritism is linked with a system related to concern over normative social practices, which is, in turn, partially associated with trait Openness.
authors.affiliation: University of York.
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Lewis
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Bates
mesh_terms: D000328:Adult; D001318:Authoritarianism; D005260:Female; D006608:Hierarchy, Social; D006801:Humans; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D009014:Morals; D010551:Personality / Q000235:genetics*; D066262:Social Norms; D011795:Surveys and Questionnaires; D014427:Twins / Q000235:genetics